Available PhD Projects in CMMP

Supervisor: David Bowler
Second supervisor: Roger Johnson
Funding source: UCL-CSC or UCL-RES or UCL-ROS or Self-funded
Submission deadline: UCL-RES and ROS 10 January 2025, UCL CSC 15 January 2025

Project description (click to expand)

This four year PhD project, which is available through the EPSRC DTP at UCL, involves application of large-scale DFT calculations through the CONQUEST code to the quadruple perovskite BiMn7O12 in which spin order, orbital order and Jahn-Teller distortions all compete, producing novel dipole textures alongside polarisation and anti-ferromagnetic order.

Ordering of magnetic dipoles in materials gives rise to many kinds of magnetic structures, from simple ferromagnetism to complex helices, that have found important applications with profound impacts in society. Electrical dipoles in dielectrics are normally associated with only simple alignment, but recent experiments at UCL have found helical order in the quadruple perovskite BiCuxMn7-xO12. This discovery has opened a completely new area for research and potential applications such as chiral optical devices that control the light-matter interaction in solid-state quantum information processing.

You will use state-of-the-art density functional theory (DFT) codes, performing simulations to explore and understand the mechanisms behind helical order, working closely with experiments at ISIS and Diamond to suggest routes to control and develop new materials and orderings. You will work with David Bowler (LCN), who leads the development of the large scale DFT code CONQUEST, and with Roger Johnson (CMMP), who leads the experimental work on BiCuxMn7-xO12. CONQUEST is a world-leading code, and has been applied to simulations with over 1,000,000 atoms (standard calculations address a few hundred atoms): it is uniquely capable of calculating complex orders. You will work to understand the phase diagram of BiCuxMn7-xO12, both pure and as it is doped with Cu. You will explore the different local dipole arrangements in the material, and use the modern theory of polarisation. These calculations will be at the very edge of what is possible with DFT, and will drive forward both large-scale DFT and our understanding of polarisation and dipole textures in dielectrics.

Supervisor: Ian Robinson
Second supervisor: Roger Johnson
Funding source: UCL-CSC or UCL-RES or UCL-ROS or Self-funded
Submission deadline: UCL-RES and ROS 10 January 2025, UCL CSC 15 January 2025

Project description (click to expland)

This PhD project will use Bragg coherent diffraction imaging (BCDI) to investigate diffusion barriers forming during the hydrogen gas reduction of small crystals of hematite and magnetite undergoing the “Steam-Iron” reaction. Hydrogen is generated by oxidizing iron with steam at high temperatures, reversibly converting oxides to iron for safe storage of its chemical energy. We will use the strain sensitivity of BCDI to obtain 3D images of strain in situ during the reaction.

You will be supervised by Professor Ian Robinson in the London Centre for Nanotechnology. Your project will start by examining how the structure of nanometre-sized crystals of hematite (Fe2O3) and magnetite (Fe3O4) change in response to hydrogen gas exposure, or water for the reverse reaction. It is known that both directions of the reaction show kinetic blockages in the reaction rate, attributed to the formation of defects of unknown nature.
Impact: By understanding the role of crystal defects in the reaction rate and cycling stability of the reaction, the interconversion of iron oxides and iron metal by hydrogen and gaseous water, we can design better storage materials. We will address two overlapping environmental planet-care goals, hydrogen storage and carbon-free steelmaking, achieving either of which will significantly reduce global CO2 emissions.

Who we are looking for: This project suits a talented and ambitious student with an interest in experimental condensed matter and materials physics. You will be trained in coherent X-ray diffraction imaging of nanocrystalline materials and will interact with the doctoral training cohort at UCL. You will use and help develop software, including Machine Learning methods, for the analysis of BCDI data. You will learn to use national central facilities, such as the Diamond Light Source, where there are also opportunities for training placements. You will publish your work and present it at conferences.

References:
"Coherent Diffraction Imaging of Strains on the Nanoscale" Nature Materials (2009)
DOI: 10.1038/nmat2400
“Anisotropy of Antiferromagnetic Domains in a Spin-orbit Mott Insulator” PRB (2023)
DOI: 10.1103/PhysRevB.108.L020403

Supervisor: Steven Schofield
Second supervisors: Mark Buitelaar (UCL), Yasin Ekinci (PSI)
Funding source: EPSRC DTP/PSI or UCL-CSC or UCL-RES or UCL-ROS or Self-funded
Submission deadline: DTP/PSI 12:30 pm 28 January 2025; UCL-RES and ROS 10 January 2025; UCL CSC 15 January 2025

Project description (click to expand)

Why this research is important. 

Quantum computing has the potential to revolutionize technology, impacting sectors from cryptography to pharmaceuticals. Realizing this potential requires breakthroughs in qubit scalability. Spin states in semiconductors are among the most stable qubits, and donor atoms in semiconductors are fundamentally identical, setting them apart for scalable quantum devices. This project will explore the fundamental science of atomic-scale germanium-based quantum systems, aiming to develop scalable quantum technology using advanced atomic-scale techniques.

Who you will work with. 

You will join a collaborative team at UCL, working closely with PhD and master’s students in the scanning tunnelling microscopy (STM) lab. Prof. Schofield will directly supervise you, alongside experts in quantum device physics. Additionally, you will conduct experiments and participate in collaborative projects at the Paul Scherrer Institute (PSI), Switzerland’s largest research institute for natural and engineering sciences.

What you will be doing. 

Your work will use cryogenic STM and advanced photoelectron methods to study quantum device fabrication in germanium. You will position donor atoms with atomic precision to create two-, one-, and zero-dimensional quantum devices for scanning tunnelling spectroscopy, photoelectron, and electronic transport measurements. Your research will also utilise PSI’s SLS 2.0 synchrotron for EUV patterning and momentum-resolved photoelectron spectroscopy.

Who we are looking for. 

We are looking for a motivated researcher with a background in physics or materials science. Ideal candidates have strong analytical skills and a collaborative approach. Training will be provided, but an enthusiasm for atomic-scale science is essential.

Key References

[1] Schofield, et al. Atomic-Scale Semiconductor Devices Roadmap 2024. Nano Futures (in press, 2024).

[2] Constantinou, et al. EUV-induced hydrogen desorption as a step towards large-scale silicon quantum device patterning. Nature Communications 15, 694 (2024).

[3] Stock, et al. Single-Atom Control of Arsenic Incorporation in Silicon for High-Yield Artificial Lattice Fabrication. Advanced Materials 23, 12282 (2024).

[4] Constantinou, et al. Momentum space imaging of ultra-thin electron liquids in δ-doped silicon. Advanced Science 10, 2302101 (2023).

[5] Hofmann, et al. Room Temperature Incorporation of Arsenic Atoms into the Germanium (001) Surface. Angewandte Chemie - International Edition 62, e202213982 (2023).

Supervisor: Arijeet Pal
Second supervisor: Andrew Fisher
Funding source: UCL-CSC or UCL-RES or UCL-ROS or Self-funded
Submission deadline: UCL-RES and ROS 10 January 2025, UCL CSC 15 January 2025

Project description (click to expand)

Emergence of universal non-equilibrium phenomena due to interaction between particles is a fundament question in physics. Quantum mechanics plays a vital role in the dynamics of interacting matter ranging from the microscopic world of atoms and electrons to large scale physical objects such as black holes. Superconductors and magnets are paradigmatic examples of emergent quantum states useful for efficient energy transmission and information storage. Recent exciting developments in both theory and experiments of interacting quantum systems have led to novel regimes of non-equilibrium matter with quantum entanglement. Entangled states host long-range correlations which are useful for quantum computing and quantum sensing, and are the precursor to next-generation materials with novel properties.

The main aim of the project will be to investigate exotic forms of entangled states emerging from out-of-equilibrium dynamics. The project would involve the study of entanglement in the presence of novel symmetries and dynamic drives, also coupled to an external environment when quantum states become fragile. The symmetries generated in dynamical systems can be controlled by tuning the strength and frequency of the drive. We would consider the interplay of topology and dynamical symmetries in stabilising long-range entanglement and protecting dissipation-free transport. The project will delve into the impact of dissipation on the robustness of entangled states and their dynamics. The problems will be tackled using analytical and computational methods. An understanding of quantum many-body physics along with some exposure to perturbative techniques, and numerical tools of exact diagonalisation and tensor networks would be desirable.

The candidate will be trained on a broad range of skills in quantum many-body physics which will be relevant to quantum materials, atomic, molecular and optical physics, and quantum information. There will be opportunities to attend summer schools and conferences, and be a part of the wider quantum ecosystem. 

Email primary supervisor if you have questions about the project or the source of funding.

Supervisor: Roger Johnson
Second supervisor: David Bowler
Funding source: EPSRC DTP or UCL-CSC or UCL-RES or UCL-ROS or Self-funded
Submission deadline: DTP 12:30 pm 28 January 2025; UCL-RES and ROS 10 January 2025; UCL CSC 15 January 2025

Project description (click to expand)

Why this research is important: 
From electric motors to advanced data storage devices, ferromagnetic materials have transformed the modern world. Building on this progress today, ‘spintronics’ promise a new paradigm of beyond-CMOS digital technology, whereby information is processed using the spin of an electron, as opposed to its charge. However, the net magnetic moment of ferromagnets imposes fundamental limits that curb potential exploitation. These limits can be circumvented if antiferromagnets are used instead, but then the absence of a net moment hinders both the ability to deterministically control microscopic domains, and the generation of a spin polarised current needed for signal processing. The recent discovery of altermagnetism marks a transformative leap in the potential application of antiferromagnets, as they may host a remarkable anisotropic spin polarisation of conduction electrons. There now remains one key scientific challenge; to find novel methods of deterministic altermagnetic domain control. 

Who you will work with:
This PhD studentship will be supervised by Dr Roger Johnson and Prof. David Bowler. The experimental work will be performed in collaboration with the XMaS beamline at the large-scale European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The project will be further enhanced through collaborations with international and industrial project partners.

What you will be doing:
The PhD student will test fundamental magnetostructural coupling schemes to establish novel methods of altermagnetic domain control. Resonant X-ray diffraction experiments will be performed on selected materials at XMaS, complemented by materials modelling calculations using density functional theory.

Who we are looking for:
We are looking to recruit an outstanding student with a strong interest in condensed matter and computational physics. Ideally, the student will have completed Masters-level courses and/or a research project in related areas. There will be scope to tailor this project to the student’s interests.

Supervisor: Venkat Kapil
Funding source: UCL-CSC or UCL-RES or UCL-ROS or Self-funded
Submission deadline: UCL-RES and ROS 10 January 2025, UCL CSC 15 January 2025

Project description (click to expand)

This PhD project aims to develop simulations based on quantum mechanics, statistical mechanics, and machine learning to explore the anomalous properties of materials in nanoscale cavities. Our focus will be on studying the phase behaviors of water in realistic nanoconfined cavities made of layered two-dimensional materials. This model system is relevant for various applications, such as energy storage, catalysis, and water treatment. We will collaborate with theoreticians and experimentalists from Cambridge, Paris, and Mainz, applying simulations to guide the discovery of new phase behaviors in experiments. If you are interested in quantum and statistical mechanics and have enthusiasm for computational methods, we invite you to join us.

Background: The properties of matter deviate dramatically from their “bulk limit” close to interfaces and when confined in cavities of nanoscale dimensions. These anomalies have widespread implications spanning everyday biological phenomena in our bodies to diverse technologically relevant processes to electronic devices, batteries, and water treatment. While the laws of quantum mechanics (QM) are sufficient to describe these anomalies, the algorithms to solve the QM equations display daunting complexity.

In the era of machine learning: Conventional so-called “first principles” simulations – that aim to treat the quantum mechanics of all electrons and nuclei – display accurate-cost limitations. Simply put, accurate simulations are too computationally expensive, while inexpensive simulations offer inadequate accuracy. However, recent developments in machine learning (ML) and artificial intelligence (AI) bypass the complexities of QM, thereby offering an unprecedented solution to simulate complex materials at the desired quantum mechanical accuracy.

Our recent breakthrough: Our recent study exploiting ML-enabled first-principles simulations has clarified the behaviour of water molecules within nanoconfined spaces, revealing characteristics vastly distinct from bulk states. These findings include new phases like a hexatic phase, an intermediate between a solid and a liquid, and a superionic phase with a greater ionic conductivity than currently used battery materials.

Your PhD goals: Your PhD will revolve around developing methodologies at the intersection of quantum mechanics, statistical mechanics, and ML/AI and their application to model the phase behaviours of water in experimentally accessible nanoconfined cavities of reasonable complexity. This methodology development will be in collaboration with quantum chemistry and ML experts at the University of Cambridge. Furthermore, to ensure our predictions are experimentally accessible, we will team up with leading fabrication and spectroscopy experts at École Normale Supérieure, Paris, and Max Planck Institute for Polymer Research, Mainz.

If you are interested in the fundamentals of quantum and statistical mechanics, have an enthusiasm for computational methods, and the above description speaks to you, please drop me a line at vk380@cam.ac.uk with the subject “Inquiry for PhD project”.

Supervisor: Carla Perez-Martinez
Second supervisor: Neal Skipper
Funding source: EPSRC DTP or UCL-CSC or UCL-RES or UCL-ROS or Self-funded
Submission deadline: DTP 12:30 pm 28 January 2025; UCL-RES and ROS 10 January 2025; UCL CSC 15 January 2025

Project Description (click to expand)

Why is this research important? The demand for electronics is unprecedented, with processors needed for consumer devices and cloud computing. Manufacturing electronics requires technologies for material removal, or etching. For example, a mobile phone accelerometer consists of silicon shaped into micrometre-sized beams and springs. To carve such small features, machines known as etchers create and direct a plasma towards a target covered with a patterned mask. In this project, you will optimise a novel etching system, based on a technology known as the Ionic Liquid Ion Source (ILIS). 

Who will you be working with? With Dr Carla Perez-Martinez in the London Centre for Nanotechnology (https://www.ucl.ac.uk/london-nano/fabrication-ionic-liquid-ion-sources)

What you will be doing? ILIS are needle devices that produce a spray of ions from ionic liquids, a type of liquid composed solely of positive and negatively charged ions. The resulting beam can be used to treat materials. A single ILIS has already been used to etch silicon with enhanced yields. Ionic liquids are non-volatile and thus an ILIS-based etcher would not require many of the safety fixtures required to handle the toxic gases used by conventional etchers. You will design, implement and test an ILIS needle array and attached optics for use in industry-scale electronics fabrication. You will be trained in charged particle physics and in COMSOL Multiphysics for simulation of the devices, and you will gain experimental skills by testing the devices in our vacuum chamber facilities. The student will irradiate silicon targets and use atomic force microscopy and other techniques to determine the uniformity of etching from the array.

Who are we looking for? Suitable candidates will have a minimum of an upper second-class UK Master’s degree in physics, electrical or electronic engineering, materials science, or a related discipline, or an equivalent overseas qualification.

Supervisor: Jochen Blumberger
Funding source: ERC
Submission deadline: 12 January 2025
 

Project description (click to expand)

A 3.5-year PhD studentship is available to work under the supervision of Prof Jochen Blumberger at the Condensed Matter and Materials Physics Laboratory, University College London, UK. The project involves the development and application of machine learning methods that enable a major boost of the time and length scales accessible to ab-initio/first principles molecular dynamics simulations. Specifically, you will further develop our recently introduced perturbed neural network potential (PNNP) approach to leverage machine learning MD simulation of condensed phase systems interacting with external electric fields. Using this methodology you will investigate how electric fields modify chemical reactivity and ion adsorption at solid/liquid interfaces at atomistic resolution. Surface sensitive vibrational spectra will be calculated to validate the predicted atomistic structures and reactivities against experimental data. The detailed molecular understanding of electric field effects at solid/liquid interfaces obtained in this work will underpin the rational design of improved electrodes and electrolytes for diverse energy conversion applications. Access to high performance computing facilities including CPU and GPU clusters will be provided throughout the project.

Interested candidates may want to take a look at our recent work on perturbed neural network potential simulations: https://www.nature.com/articles/s41467-024-52491-3 

Highly motivated students from Physics, Chemistry or Materials Science Departments are strongly encouraged to apply for this post. The candidate should have, or be about to receive, an honours degree (at least II.1 or equivalent) in Physics, Chemistry or a related subject. Good knowledge in quantum mechanics and statistical mechanics is expected. Some experience with molecular simulation and scripting languages (e.g. python) is a plus. 

The start date of the studentship is 22. September 2025. The studentship will cover all university fees and includes funds for maintenance at the standard UK rate and for participation in conferences and workshops. Due to funding restrictions, this studentship is open only to candidates from the UK or from the EU with pre-settled status in the UK. Please refer to the following website for eligibility criteria: https://www.ucl.ac.uk/prospective-students/graduate/research-degrees/phy...

Please submit applications in the following format:

• A personal statement (500 words maximum) outlining (i) your suitability for the project, with reference to the criteria in the above person specification, (ii) your research experience to date, (iii) what you hope to achieve in your PhD. 

• A CV, including full details of all University course grades to date, and, if relevant, details on scholarships, prizes and scientific papers published or in preparation. 

• Academic transcripts for undergraduate (Bachelor) and graduate (Master) studies.

• Names, and email addresses of two academic or professional referees (at least one academic).

These four documents should be submitted as a single zip file to Jochen Blumberger at j.blumberger@ucl.ac.uk specifying in the subject line “PhD application”. The closing date for applications is 12. January 2025. All applications received by this date will be considered. Applications received after this date may be considered only if a suitable candidate has not been found by the above closing date. 

Informal enquiries regarding the vacancy can be made to Jochen Blumberger, j.blumberger@ucl.ac.uk

Supervisor: Jonathan Breeze
Second supervisor: Chris Kay
Funding source: UCL Department of Physics and Astronomy
Submission deadline: 10 January 2025
 

Project description (click to expand)

Applications are invited from candidates with UK-settled (home) status for a fully-funded 3.5-year PhD studentship in solid-state quantum optics under the supervision of Dr Jonathan Breeze in the Department of Physics & Astronomy, University College London, UK. 

The project involves the development and application of diamond masers [1], solid-state quantum optics and cavity quantum electrodynamics [2].

The maser was the microwave progenitor of the now ubiquitous laser but was hampered in its development by the need for cryogenic refrigeration and high vacuum systems.  Despite this it found application in deep-space communications and radio astronomy due to its unparalleled low-noise when used as an amplifier.  UCL recently demonstrated a diamond maser – the first continuous-wave room-temperature solid-state maser using engineered quantum defects in synthetic diamond.  These defects, known as nitrogen-vacancy (NV) centres can serve as solid-state quantum bits (qubits) for quantum information processing, quantum optics and quantum sensing.  Diamond masers could find application in a diverse array of field, from magnetic resonance imaging, quantum sensing, quantum computing, communications, security and metrology.

The project will use experimental techniques such as pulse electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR) and optically detected magnetic resonance (ODMR) to characterise spin-defects in candidate materials and apply theoretical techniques from quantum optics and cavity quantum electrodynamics to describe their behaviour when coupled to microwave photons.

In addition to working in Dr Breeze’s group at UCL you will also be be collaborating with groups in the UK, Germany, Italy and the USA. You will also have the opportunity to be involved in the new UK quantum research hub in Quantum Biosensing [3].

This project would suit a highly motivated student in Physics, Electrical Engineering, Chemistry or Materials Science with a good mix of experimental, theoretical and computational capabilities who enjoys designing and building theory-led experiments.  Being proficient in Python programming and an aptitude for quantum theory, electronics or instrumentation would be beneficial. Enquiries regarding the studentship can be made to Jonathan Breeze (j.breeze@ucl.ac.uk). 

[1] J.D. Breeze et al, Nature, 555, pp. 493–496 (2018)
[2] J.D. Breeze et al, npj Quantum Information, 3, 40 (2017)
[3] https://www.qbiomed.org.uk/